Transmission



March 9, 1948. w. l.. PoLLARD TRANSMISSION 'Filed Aug. 29. 194:2

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UNITED `STATES PATENT AOFFICE TRANSMISSION Willard L. Pollard, Evanston, lll. Application August 29, 1942, Serial No. 456,594

7 Claims. (Cl. 'I4-189.5)

My invention relates to transmissions.

An object o1' my invention is to lprovide an improved hydro planetary transmission capable of having a plurality of dill'erent torque ratios with provision for changing smoothly from one ratio to another.

A further object is to provide such a construction which will be relatively simple in operation, inexpensive to manufacture and durable in use.

A further object is to provide such a construction in which a change of ratio is eiIected without the use of direct-contact friction-gripping means or dog clutches.

A further object is to provide such a construction which will enable the motor to idle without causing the car to creep.`

A further object is to provide such a construction which will hold the car against backing down on upgrades.

A further .object is to provide such a construction which will provide a simple, continuous powy er flow.

A further object is to provide such a construction in which a substantial proportion of the power may be by-passed around the hydraulic part of the transmission.

Further objects and advantages of the invention will be apparent from the description and claims.

In the drawings, in which several forms of my invention are shown, f

Figure 1 is an axial sectional view of a hydraulic planetary transmission;

Fig. 2 is an axial sectional view of a control valve;

Fig, 3 is an axial sectional view showing another form of transmission; v

Fig. 4 is an enlarged detail view showing a modification of Fig. 2; and

Fig. 5 is an axial sectional view showing another form.

Referring `:first to Figs. 1 and 2, the construction shown comprises a rotary drive member I, a driven shaft 2, an intermediate shaft 3, a duplex pump rotor I secured to rotate with the drive member I, aturbine rotor 5 secured to the intermediate shaft 3 and'driven from the front pump rotor 6, a turbine rotor 1 driven from the rear pump rotor 8. and secured to a sleeve 9 on which the sun gear I0 is `keyed, a :duid-trans- 2 mitting torque-transmitting rotor II keyed to the intermediate shaft 3, a one-way anchorage device I2 for preventing reverse rotation of the sun gear, a, one-way anchorage device I3 for preventing reverse rotation of the torque-transmitting fluid-transmitting rotor II, a ring gear I4 secured to the intermediate shaft-3, a gear carrier I5 secured to rotate with the driven shaft 2, and planet gearing I6 carried by the gear carrier and meshing with the sun gear and ring gear. The rotor II may be of the type shown in my copending application Serial No. 410,815, filed September 15, 1941, now Patent #2,322,251, June 22, 1943, comprising a circular plate ISa having two concentric series' of circumferential openings ISb and I6c therein for the passage of liquid between the rotors l and 8 and a circular dished rotor IBd connecting the plate I 6a with the sleeve 22. 'Suitable antifriction bearings Il are pro- 80 vided between the various rotors. Suitable leak stops I8 are provided tc prevent the escape of liquid from the hydraulic part of the transmission.

vSuitable means are provided for filling and 8l emptying the chambers I 9 and 20. Such filling and emptying devices are old and well known in this art and need not be described in detail. The filling and emptying of the two liquid chambers are controlled by the valve construction shown 30 in Fig. 2, as described more in detail hereinafter.

This valve mechanism can be operated so that both liquid chambers will be empty in one position of the valve 2l; so that the rear chamber 20 will be full and the front chamber I9 empty in 5 another position of the valve; so that the front chamber I8 will be full and the rear chamber 20 empty in another position of the valve, and so that both chambers will be full in another position of the valve.

In the first position of the valve, with both chambers empty, no torque will be transmitted. In the second position, with the rear chamber full and the front chamber empty, no torque will be transmitted to the ring gear I4which, how- 5 ever, will be held against reverse rotation by the one-way anchorage device Iiactlng through the sleeve 22, the torque-transmitting rotor II and the intermediate shaft 3. The sun gear I 0 will be rotated since the rear chamber 20 .is full of liquid and the rear hydraulic coupler is active and effective. This will give a relatively low v speed depending upon the ratio between the sun gear III and the ring gear I4. In the third position of the valve, with the rear chamber 28 empty and the front chamber Il full, no torque will be exerted on the sun gear which, however, will be held against reverse rotation by the one-way anchorage device I2. Torque will be exerted on the ring gear I4 from the pump rotor 8 to the turbine rotor 5 andintermediate shaft 3. This will give an intermediate speed ratio, depending on the ratio between the ring gear I4 and the sun gear I8. In the fourth position of the valve, both chambers will be full of liquid and both the sun gear and ring gear will be-driven, the sun gear being driven from the rear pump rotor 8 of the turbine rotor 1 and the ring gear being driven from the front turbine rotor II.

Referring somewhat in detail to the valve shown in Fig. 2, let it be assumed that the slide valve 2| is in the second position, for low gear, in which it connects a branch 23 of the conduit 24 with the conduit 25 and that the conduit 25 is connected with a conduit 28 leading to the annular supply chamber 21 for the rear fluid chamber 20. Let it be assumed that if the slide valve is moved one step to the left, it will bring the annular passage 28 into registration with the branches 29 and 38, which will connect the conduit 24 with the conduit 3l leading to the conduit 32 connected with the annular supply passage 33 for' the front liquid chamber I8. Further let it be assumed that if the slide valve 2| is moved two steps to the left from the posi- Y tion shown, it will bring the annular passage 28 into registration with the branch 34 of the conduit 29 and with the branch 35 of the conduit 3| and will bring the annular passage 38 into registration with the branch 23 and with the conduit 25 which is connected withrthe conduit 26. Let it also be assumed that if the slide valve 2| is moved from the position shown one step to the right, none of the conduits 25 and 3| will be in communication with the conduit 24. Further let it be assumed that when the conduit 24 is in communication with the conduit 25, the rear liquid chamber 20 will be nlled and, when not in communication, the rear chamber will be empty. Let it also be assumed that when the conduit'24 is in communication with the conduit 3|, the front liquid chamber I9 will be nlled and, when not in communication, the front chamber I9 will be empty.

Under these conditions, it will be seen that when the slide valve is in the position shown,

the front chamber I9 will be empty and the rear' chamber 20 will be full and the transmission will be in low gear; that if the valve is moved one step to the'left, the front chamber will be full and the rear chamber empty and the transmission will be in intermediate gear, and that if the valve is moved two steps to the left, the transmission will be in high gear or direct drive. If the slide valve is moved one step to the right from the position shown, none of the conduits 25 and 3| will be in communication with the conduit 24, both chambers I9 and 20 will be empty and no power will be transmitted. It will be noted, however, that the one-way anchorage devices I2 and I3 would prevent the car from backing downhill if it were stopped on an upgrade by preventing reverse rotation of the sun gear i0 and ring gear I4 and hence of the gear carrier I5 and driven propeller shaft 2. It will be seen that this construction provides three usable gear 4 i ratios, using a simple planetary in combination with a simple hydraulic power transmitter without the use of friction clutches or dog clutch and obtaining continuous power flow.

The construction shown in Fig. 3 comprises a drive shaft 40, a driven shaft 4I, a front pump rotor 42 keyed to the drive sh'aftlli, afront turbine rotor 43 keyed to the sleeve 44 on which the ring gear 45 is keyed, a rear pump rotor 48 driven from and rotatable with the front turbine rotor 43, a rear turbine rotor 41 driven from the rear pump rotor 48 and keyed to the sun gear 48, a one-way anchorage 49 for holding the sun gear 48 against rotation, a sun gear 50 keyed to the drive shaft 40, a gear carrier 5I rotatable on the driven shaft 4I, planet gearing 52 meshing with the sun gear 50 and ring gear 45, a ring gear 53 rotatable with the gear carrier 5I, a gear carrier 54 keyed to the driven shaft 4I.' and planet gearing 55 carried by the gear carrier 54 and meshing with the sun gear 48 and ring gear 53.

Means are provided for filling and emptying the liquid chambers 55 and 51 from the front and rear couplers which may, in general, be similar to the means for filling and emptying described in connection with Figs. 1 and 2. 'Ihe conduits 25a and 32a correspond to the conduits 29 and 32, respectively, of Fig. i. Suitable leak stops I8 may be provided as in Fig. l. With this construction, a number of conditions can exist with respect to the filling and emptying of the liquid chambers: (1) Both may be empty in one condition; (2) the front one may be empty and the rear one iull in another condition; (3) the front one may be full and the rear one empty in another condition, and (4) both may be full in another condition. Under the first condition, there will, of course, be no torque exerted on either the turbine 43 or the turbine 41 so that parts of the planetary mechanism will revolve idly. Under the second condition, with the front chamber.

empty and the rear chamber full, the driven shaft 4I may remain stationary at slow speeds of the drive shaft, the sun gear 50 rotating with the shaft 48, the sun gear 48 being held against rotation by the one-way anchor 49 and the rotors 43 and 46 revolving at a relatively slow speed in a reverse direction, which reverse rotation will be resisted to some extent by the turbine rotor 41 which is held against reverse rotation by the one-way anchor 49. However, ii the motor picks up above idling speed, the speed of the reverse rotation of the pump rotor 46 will become so great that the drag exerted by the stationary turbine rotor 41 will cause suiilcient resistance to the reverse rotation of the pump rotor 46 to cause the driven shaft to start rotating. A With the gear proportions shown. the torque ratio of drive shaft to driven shaft under these conditions will be about .28 to 1.

If, now, the front chamber is filled with liquid, so that both chambers are full and the fourth condition exists, the rotors 43 and 48 will slow up their reverse direction, come to a standstill and then go into a'forward rotation. At the instant of transition from reverse to forward rotation, the ratio of drive shaft torque to driven shaft torque, with the gear proportions shown, will be about .4. If the speed of the motor continues to increase, the speed of the rotors 43 and 45 will increase to a point at which the second turbine rotor 41 will start to rotate, and if the speed still continues to pick up. the transmission will go into substantially a direct drive.

If it should be desired to obtain a sudden burst of. power, the rear coupler could be emptied of liquid, resulting in the third condition, whereupon the tubular shaft 58 and sun'gear 48 would slip back onto the one-.way anchorage 48 and the rear coupler would then be eliminated as a factor, power flow from the drive shaft 48 to the driven shaft 4| being divided, part going through the hydraulic part of the transmission and part being by-passed. With the proportions shown, the torque ratio under these conditions between the drive shaft and the propeller shaft would be approximately .7 to l.

In low gear, approximately 40 per cent of the power is by-passed around the hydraulic part of the transmission; also at intermediate gear. approximately 40 per cent is by-passed. In high gear, approximately 28 per cent is by-passed. The rear coupler never has to handle more than .3 of the motor torque, and the front coupler never has to handle more than 'I2 per cent of the motor torque, 'I'his enables the rear coupler to be made relatively small. In order to slow down in going downhill when the car is driving the motor, a brake 48 may be provided which can be applied to hold the rotors 4l and 48 and the gear 45 against rotation, both chambers 55 and 51 being lled. Under this condition, the rotors 43 and 46 will act as a drag on the rotors 42 and 41, respectively, and hence will act as a drag on the gears 58 and 48, respectively.

In Fig. 4 is shown a modification .of the construction shown in Fig. 3, the one-way anchorage device 49 being shifted from engagement with the sleeve 58 of the sun gear 48 to engagement with a hub portion 59 on the combination turbine and pump rotor 43 and 46, the rest of the structure of Fig. 2 being unchanged. With this construction, with both chambers 58 and 51 empty,

no torque will be transmitted by either of the hydraulic couplers, and certain of the planetary gears will rotate idly without transmitting any torque from the drive shaft to the driven shaft. If the front chamber is empty and the rear chamber is full, the one-way anchorage 49 will hold the ring gear 45 -against reverse rotation and the sun gear 58 will be driven directly by K the motor. This will cause the cage 5i and ring gear 53 to revolve at a relatively low speed, depending upon the ratio of the sun gear and ring gear. This rotationk of the ring gear 53 will cause a reverse rotation. of the sun gear 48 and rotor 41, due to the resistance of the driven shaft 4l acting through the gear carrier 54 and planet gearing 55. This reverse rotation of the rotor 41 and sun gear 48 will ,be resisted by the drag exerted on the turbine rotor by the pump rotor 48.

which is held against reverse rotation by the oneway anchor 48.- This resistance to reveres rotation of the sun gear 48 will cooperate with the action of the ring gear to cause the gear carrier 54 to rotate in a forward direction carrying with it the driven shaft 5i. This will give a torque multiplication of about 4.5. If, now, both chambers are filled with liquid, the pump rotor 42 will cause the turbine rotor 48 to start rotating, carrying with'it the ring gear 45.V As the first turbine rotor 43 increases in speed, the second pump rotor 46 increases in speed also and will eventually cause the second turbine rotor 41 to start rotating. The turbine rotors 48 and 41 may increase in speed until both are rotating at slightly less speed than the drive shaftl 48.

The construction shown in Fig. 5 comprises a drive shaft18, a driven shaft 1I, an intermediate shaft 12, a pump rotor 18 keyed to the drive shaft 12, planet gearing 18 carried by the gear carrier 11 and meshing with the sun gear 15 and ring gear 18, a pump rotor 19 keyed to the intermediate shaft 12, a combination turbine and pump rotor 80 keyed to the sleeve` 8| on which the sun gear 82 is secured, a turbine rotor 8l keyed to a sleeve 84 which is held against reverse rotation by the one-way anchorage 85, a oneway anchorage 85 for holding the sun'gear 15 against reverserotation, a ring gear 81 secured to the intermediate shaft 12, a gear carrier 88 keyed to the driven shaft 1| and planet gearing 88 carried by the gear carrier 88 and meshing with the sun gear 82 and ring gear 81.

Means maybe provided for filling and emptying the liquid chamber of the front coupler 18, 14.' When both liquid chambers are full and the motor is put in operation and picks up in speed, the ring gear 18 will rotate with the motor shaft 18 and the sun gear 15 will be held against reverse rotation by the one-way anchorage 88 until the drag of the pump 13 on the turbine 14 starts Vthe sun gear 15 to rotating. This will cause rotation of the gear carrier 11, intermediate shaft 12' and ring gear 81. The rotation of the ring gear will first cause reverse rotation of the sun gear 82 due to the resistance to motion of the driven shaft 1i and gear carrier 88. This reverse rotation of the sun gear 82 will be resisted by the Vdragging action of the turbine rotor 83 on the pump rotor 88, the turbine rotor 88 being held against reverse rotation by the one- Way anchorage 85. It will be seen that at rst there will be two speed reductions in series so that the total speed reduction will be the product of the two speed reductions.

As the pump rotor 13 picks up in speed, it will start the turbine rotor vlill to rotating and with it the sun gear 15. The turbine rotor 14 will continue to pick up in speed until its speed approximates that of the pump rotor 13. This will cause the speed of the gear carrier 11 to increase and with it the speed of the pump rotor 18 and ring gear 81. As the speed of this pump rotor18 increases, it will exert an increasing pull on the turbine ."1 to slow up the reverse rotation of the turbine and pump rotor 88, cause it to come to a standstill and then rotate in the same direction as that of the pump rotor '18. As soon as the combination turbine and pump rotor 88 starts to rotate in a forward direction, the turbine rotor 83 will free itself from the 'one-way anchorage 85 and rotate idly along with the combination rotor 80. Under ordinary conditions, the turbine speeds will continue to increase until they approximate the speeds of the pump rotors and the entire transmission rotates substantially as a unit.

If desired, means may be provided similar to those disclosed in connection with Figs. 1 and 2 for filling and emptying the front liquid chamber When'desired. If the front chamber is emptied. the front coupler` is disabled and the sun gear 15 falls back onto the one-way anchorage 88, thus eiecting a direct gear drive between the drive shaft and the intermediate shaft.

It will be noted that in both the front coupler ,and the rear coupler, substantially two-thirds of thepower is by-passed around the hydraulic part of the transmission.

Further modications will be apparent to those skilled in the art and it is desired, therefore 'that the invention be limited only by the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A hydro planetary transmission comprising rotatable drive means, pump rotor means driven from said drive means, turbine rotor means driven from said pump rotor means, planetary gearing comprising a first gear, a second gear coaxial therewith, and means in Iorce-transmit-- ting relation between said gears including a gear carrier and planet gearing carried by said carrier, said pump rotor means and turbine rotor means comprising a ilrst pump rotor driven positively by said drive means, a ilrst turbine rotor drivable by said first pump rotor, a second pump rotor driven positively by said ilrst turbine rotor, and a second turbine rotor drivable by said second pump rotor, said second gear being driven positively from said first turbine, said nrst gear being driven positively from said drive means, means for holding said second turbine against reverse rotation with respect to the direction of its pump driven rotation, a third gear driven by said second turbine, a fourth gear driven by said gear carrier, a second gear carrier, and planet gearing carried by said second gear carrier and meshing with said third and fourth gears.

2. A hydro planetary transmission comprising rotatable drive means,-pump rotor means driven from said drive means, turbine rotor means driven from said pump rotor means, planetary gearing comprising a rst gear, a second gear coaxial therewith, and means in force-transmitting relation between said gears including a gear carrier and planet gearing carried by said carrier, said turbine rotor means including two independently rotatable turbines, means for supplying and withdrawing drive liquid with respect to either` turbine selectively and for supplying and withdrawing drive liquid with respect to both turbines collectively, said first gear being driven by one of said turbines, said second gear being driven by the other of said turbines, .and one-way anchorage means for holding each gear against reverse rotation with respect to its direction of driven rotation when the driving liquid is withdrawn from its driving turbine.

3. A hydro planetary transmission comprising rotatable drive means, pump rotor means driven from said drive means, turbine rotor means driven from said pump rotor means, planetary gearing comprising a first gear, a second gear coaxial therewith, and means in force-transmitting relation between said gears including a gear carrier and planet gearing carried by said carrier, said turbine rotor means including two independently rotatable turbines, means for supplying and withdrawing drive liquid with respect to either turbine selectively and for supplying and withdrawing drive liquid with respect to both turbines collectively, said rst gear being driven by one of said turbines, said second gear being driven by the other of said turbines, and means for holding each gear against reverse rotation with respect to its direction of driven rotation when the driving liquid is withdrawn from its driving turbine.

4. A hydro planetary transmission comprising rotatable drive means, pump rotor means driven from said drive means. turbine rotor means driven from said pump rotor means. planetary gearing comprising a rst gear. a second gear coaxial therewith, and means in'force-transmitting. relation between said gearsv including a gear carrier and planet gearing carried by said carrier. said turbine rotor means including two independently rotatable turbines, means for supplying and withdrawing drive liquid with respect to either turbine selectively and for supplying and withdrawing drive liquid with respect to both turbines collectively, said rst gear being driven by one oi said turbines, said second gear being driven by the other of said turbines, and means for holding each gear against reverse rotation with respect to its direction of driven rotation when the driving liquid is withdrawn from its driving turbine, said holding means comprising a liquid-transmitting torque-transmitting rotor extending across the spaces between the pump rotor means and one of said turbines and connected with one of said gears.

5. A hydro planetary transmission comprising a rotatable drive member, a pump rotor positively driven from said drive member, a gear positively driven from said drive member, a turbine rotor impositively driven from said pump rotor, a second gear positively driven from said turbine rotor, a one-way anchorage for preventing reverse rotation of said turbine driven gear, a gear carrier, planet gearing carried by said gear carrier and in force-transmission relation with respect to both said gears, a second pump rotor driven positively from said gear carrier, a third gear driven positively from said gear carrier, a second turbine rotor driven impositi'vely from said second pump rotor, a fourth gear driven positively from said second turbine rotor, a third pump rotor driven positively from said second turbine rotor, a third turbine rotor driven impositively from said third pump rotor, a one-way anchorage for preventing reverse rotation of said third turbine rotor, a gear carrier, and planet gearing carried by said carrier and in force-transmission relation with respect to said third and fourth gear.

6. A hydro planetary transmission comprising rotatable drive means, hydraulic torque transmission means, planetary gearing comprising a ilrst gear, a second gear coaxial therewith, and means in force-transmitting relation between said gears including a gear carrier and planet gearing carried by said carrier, said hydraulic torque transmission means comprising a ilrst pump rotor driven positively by said drive means, a rst turbine rotor drivable by said rst pump rotor, a second pump rotor driven posi-tively by said rst turbine rotor, and a second turbine rotor drivable by said second pump rotor, said second gear being driven positively from said first turbine, said first gear being driven positively from said drive means, and one-way anchorage means for holding said second turbine against reverse rotation with respect to the direction of its pump driven rotation.

7. A hydro planetary transmission comprising rotatable drive means, hydraulic torque transmission means, planetary gearing comprising a ilrst gear, a second gear coaxial therewith, and means in force-transmitting relation between said gears including a gear carrier and planet gearing carried by said carrier, said hydraulic torque transmission means comprising a first pump rotor driven positively by said drive means, a first turbine rotor drivable by said first pump rotor, a second pump rotor driven positively by said rst turbine rotor, and a second turbine rotor drivable by said second pump rotor, said second gear 'being driven positively from said rst turbine, said rst gear being driven positively from said drive means. and means for holding said second turbine against reverse rotation with Number respect to the direction of its pump driven rota- 2,144,256 tiom 2,147,528 l WILLARD L. POLLARD. 2,158,557 A 5 2,309,912 REFERENCES CITED 2,322,251 The following references are of record in the -2341512 me of this patent: i 21343509 UNITED STATES PATENTS lo Number Name V Date Number 2,078,287 semola -.--Apn 27, 1937 464,570 Dumem May 25, 1937 464,775

Name Date Dufleld Jan. 17, 1939 Fottinger Feb. 14, 1939 Lammeren May'16, 1939 Lazaga Feb. 2, 1943 Pollard v June 22, 1943 Burtnett Feb. 15, 1944 Jandasek Mar. 7, 1944 FOREIGN PATENTS Country Date Great Britain Apr. 19, 1937 Great Britain Apr. 23, 1937 

